I have the same problem. I've had the Pro with the standard keyboard for about 3 weeks. I habitually put it in Hibernate mode using the power button (a historical habit) and then fold the keyboard over. Often, but not always, I have the unresponsive keyboard problem described above on restart.
Another curiosity: Device Manager shows five "Surface HID Keyboard" entries under the Keyboards node. Is this normal?
The "Location" in the General property page varies. In order:
- on Surface Button VHF HID Device
- on Surface Button Converted Portable Button Device
- Location 2
- Location 1
- on Surface Button Converted Portable Button Device
In the Events tab they were configured on different dates: 1, 2, and 5 long before the device was shipped to me, and 3 & 4 when I first connected it.
It seems several people have reported exactly this issue in recent weeks. We can't all have bad keyboards?